There are already known various constructions of devices capable of transforming various external parameters by altering the flow of a fluid through the device. One device of this type is disclosed in the commonly owned U. S. Pat. No. 4,610,274 where the external parameter is the intensity of laser light that is directed into one of two inlet channels arranged upstream of an input nozzle to heat a light-absorbing zone which, in turn, warms up the fluid flowing past such zone and thus influences the flow of the fluid downstream of this zone into, through and beyond the nozzle and then as a jet stream emerging from the nozzle into a vented interaction passage substantially in the longitudinal direction of the interaction passage to one or both of two outlets. In this device, the heat imparted to the fluid at the light-absorbing zone reduces the thickness of the boundary layer at the adjacent wall bounding the respective inlet channel and this ultimately results in a deflection of the jet stream transversely of the interaction passage so that the fluid enters one of the outlet channels in an amount and/or at a pressure exceeding that or those applicable to the other outlet channel. Then, the magnitude of the optical signal determines the difference between the flow or pressure conditions in the two outlet channels.
While this opto-fluidic device operates to satisfaction in many applications, experience has shown that at least in some instances the difference between the monitored conditions in the two outlet channels is too small to give adequate power to actuate hydromechanical devices.
Accordingly, it is a general object of the present invention to avoid the disadvantages of the prior art.
More particularly, it is an object of the present invention to provide an opto-fluidic device which does not possess the disadvantages of the known device of this kind.
Still another object of the present invention is to develop the opto-fluidic device of the type here under consideration in such a manner as to enhance the differential between its output values for the same value of the optical input signal.
It is yet another object of the present invention to devise an opto-fluidic device of the above type which has an improved power conversion efficiency as compared to prior art devices of this type.
A concomitant object of the present invention is design the opto-fluidic device of the above type in such a manner as to be relatively simple in construction, inexpensive to manufacture, easy to use, and yet reliable in operation.